Metal/oxide interfaces and their reaction with hydrogen

Recent results are presented on the chemical composition of metal/oxide interfaces using the tomographic atom probe and small angle neutron scattering for both Pd/MgO and Ag/MgO interfaces. The amount of segregated oxygen and hydrogen at the interfaces is in agreement with a model of structural vacancies at dense-packed interface planes. Different to Ag-Mg internally oxidized Pd-Mg alloys swell during internal oxidation as well as during vacuum annealing above 400 degreesC and after the internal oxidation. This behavior is explained by the formation of water bubbles from excess oxygen and residual hydrogen.